In this note we wish to report a general teaching methodology which correlates the most common analytical data with Relative Standard Deviation (RSD). Then there data of RSD can be introduced in standard regression software like Origin Pro 8.0, enabling the analytical ability of the Physico-Chemical experiments which are in the syllabus of our Physical Chemistry teaching approach.
Category:Chemistry

A Simultaneous Interpretation of Existing Data on Non-Ideality of Gases and Solutions; Simple Equations of State Without Empirical Concepts and Parameters; Langmuir Isotherm for Three Dimensions (Dedicated to the Memory of J.H. Van’t Hoff)

Authors:Raji HeyrovskaComments: 46 Pages. This fundamental paper in 1984, was approved by the Editor but not by the referee. Eventually published elsewhere: Complete list in: http://vixra.org/abs/1603.0133

Existing data on the actual pressure, volume, temperature (for gases) and osmotic pressure, molar volume, temperature (for solutions) are described by simple analogous equations of state, valid for low as well as high concentrations. Deviations from ideality are ascribed to a) the volume of gas molecules, b) solvation and c) molecular and ionic association and dissociation as a result of intermolecular and interionic forces.Other main findings supporting the above conclusions are 1) a simple quantitative relation between equivalent conductivity, degree of dissociation and osmotic pressure, 2) linear dependence of the product of concentration and the coefficients of diffusion and viscosity on the osmotic pressure, 3) linear dependence of the e.m.f. of concentration cells on the logarithm of osmotic pressure, with the slope depending on solvent polarization and 4) quantitative fit of the Langmuir isotherm for occupation of space. As a consequence of the above, representation of non-ideality by activity and fugacity coefficients is not necessary. (This was originally submitted to Coll.Czechsl.Chem.Communs. in 1984, see comments.)
Category:Chemistry

Comments on The Pitzer Equations Formulated on the Assumption of Complete Dissociation of Strong Electrolytes

Authors:Raji HeyrovskaComments: 3 Pages. This short paper was accepted for publication in JPCRD, but its publication was stopped by NIST after it was proof-read. Over the years it has proved to be correct; see Structural Chem. 24 (2013) 1895-1901; DOI 10.1007/s11224-013-0256-7.

In the past years many articles have been pub¬lished in JPCRD which are based on the Pitzer equations formulated on the assumption of complete dissociation of strong electrolytes at all concentrations. However, in this current author’s opinion, these equations are so complex that they suggest that mere is some concep¬tual error. To quote some articles in Chemistry in Britain, Franks points out that “tinkering with the Debye-Hückel equation may produce better fits to experimental data over increasingly wider ranges of concentration, but it is only a curve fitting exercise." According to this current author, the above complex state of the mathematical description of the solution properties is due to the conventional assumption that strong electrolytes are completely dissociated in aqueous solutions. In recent years, it has been shown by the present author that strong electrolytes are indeed only partially dissociated in aqueous solutions, and this has been confirmed experimentally and supported by molecular dynamic simulations for saturated solutions.
Category:Chemistry